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Biomedical subjects

M Katayama

Publications and source records attributed to M Katayama.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Idiopathic intracranial hypotension associated with decreased blood concentration of vitamin A].

We report a case of idiopathic intracranial hypotension, a clinically rare syndrome. A 28-year-old woman was admitted with orthostatic headaches associated with nausea secondary to intracranial hypotension. Lumbar puncture yielded an opening pressure of 4 cmH2O in the lateral recumbent position, and the spinal fluid protein concentration was 56 mg/dl. There was no history of lumbar puncture or clear history of head trauma before the onset of symptoms. Spinal and cranial MRI showed no evidence of CSF leakage, and there was diffuse meningeal enhancement following gadolinium infusion. Cranial MRI showed no evidence of brain displacement due to low CSF pressure, such as tonsillar herniation. Radioisotope cisternography (RIC) showed rapid accumulation of isotope within the bladder and early disappearance of radioactivity from the head. About 2 months later the headaches resolved spontaneously, and repeated lumbar puncture yielded opening pressure elevation to 10.5 cmH2O with a decrease in protein concentration to 28 mg/dl. The abnormal MRI and RIC findings had become normal. On the other hand, the patient had a low blood concentration of vitamin A, which is thought to play some role in the production of CSF. The results of RIC suggested that the patient may have become symptomatic because of undetectable CSF leakage or hyperabsorption, but diminished production of CSF due to lower blood vitamin A concentrations may also have been a factor predisposing to this syndrome.

Adult↗
PubMed1995

Tonic vibration reflex and muscle afferent block in writer's cramp.

Patients with focal dystonia take advantage of certain cutaneous or proprioceptive sensory inputs to alleviate their symptoms ("sensory trick"). We examined the effects of increasing muscle spindle activity by the tonic vibration reflex maneuver and decreasing it by intramuscular injection of lidocaine. The vibration was applied to the palm or the tendon of forearm muscles in 15 patients with writer's cramp and 15 age-matched normal subjects. In 11 patients, the vibration induced dystonic postures or movements typical of those seen during writing. Normal subjects showed either no response to the vibration or a gradually developing tonic vibration reflex only in the wrist and finger flexors, which produced visible movements with a significantly longer latency (12.5 +/- 6.7 seconds [mean +/- standard deviation]) than what was observed in the patients (2.7 +/- 2.5 seconds, p < 0.0001). Local injection of lidocaine (0.5%, 5-40 ml/muscle) attenuated the tendon reflex with relatively little effect on the M response. Injection into muscles with increased activity produced marked reduction of dystonic movements and significant clinical improvement in 13 patients, whereas injection into the other muscles had no effect. The clinical benefit lasted for 1 to 24 hours after injection. In 13 patients who had additional injections of 10% ethanol, which blocks sodium channels for a longer period than does lidocaine, the duration of action was prolonged to 5 to 21 days. These findings suggest that muscles causing dystonic movements have abnormal sensitivities to vibration at rest and that muscle afferents may play a pivotal role in producing dystonic movements.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Effects of basic fibroblast growth factor on proliferation, the expression of osteonectin (SPARC) and alkaline phosphatase, and calcification in cultures of human pulp cells.

Basic fibroblast growth factor (bFGF) may be involved in the development and repair of dentine and pulp because bFGF, its related peptides, and FGF receptors are expressed in dental mesenchymal cells. In this study, we examined the effects of bFGF on DNA synthesis, osteonectin/SPARC levels, alkaline phosphatase (ALPase) activity, their mRNA levels, and calcium levels in cultures of human pulp cells. Pulp cells were isolated from three healthy upper wisdom teeth of three patients and maintained separately. These cells produced SPARC, ALPase, and calcified nodules and there was a close correlation between the SPARC-synthetic activity of the cell lines and their levels of ALPase and calcification. The levels of SPARC, ALPase and calcium deposits in the three pulp cell cultures were 10-250 times those of human foreskin fibroblasts. Western blots showed that the pulp cells produced 38-kDa SPARC. Northern blots showed that the pulp cells expressed flg (FGF receptor type 1) transcripts throughout all culture stages, irrespective of the presence or absence of bFGF. The addition of bFGF to the pulp cultures suppressed the increases in ALPase activity, SPARC synthesis, and their mRNA levels, although it increased the incorporation of [3H]thymidine into DNA > 10-fold. The effects of bFGF on ALPase activity and SPARC synthesis were reversible. Furthermore, bFGF abolished the calcification of the extracellular matrix; the calcium content of bFGF-free cultures. These findings suggest that bFGF is a potent mitogen for human pulp cells and that it inhibits the expression of the odontoblast phenotype by the cells at least partly at pretranslational levels.

Alkaline Phosphatase↗
PubMed1995

Lymph flow and lymph node metastasis in esophageal cancer.

This paper delineates which lymph nodes should be dissected due to the high frequency of metastasis associated with different types of primarily lesions of the thoracic esophagus. In cancer involving the upper third of the esophagus (Iu), lymph flow was found to be primary from the superior mediastinal area to the cervical area; in that involving the middle third (Im), it was broadly distributed from the superior, middle, and inferior mediastinal region to the cervical and abdominal regions; and in that involving the lower third (Ei), it tended to extend from the inferior mediastinal region to the abdominal region, with single primary metastatic nodes also being noted in this area. The significance of the "top" nodes, namely, the nodes located along the right recurrent laryngeal nerve in the upper portion of the thorax, was also investigated, and it was confirmed that the prognosis for patients with metastases to both the top nodes and other nodes was unfavorable. An immunohistochemical study on mediastinal lymph flow using the anti-Su-Ps antibody demonstrated interactions between top nodes and cervical and/or thoracic nodes.

Adenocarcinoma↗
PubMed1995

Inositol 1,4,5-trisphosphate formation and ryanodine-sensitive oscillations of cytosolic free Ca2+ concentrations in neuroblastoma x fibroblast hybrid NL308 cells expressing m2 and m4 muscarinic acetylcholine receptor subtypes.

Intracellular free Ca2+ concentrations ([Ca2+]i) were measured in subclones of NL308 neuroblastoma x fibroblast hybrid cells expressing each of the individual muscarinic acetylcholine receptor (mAChR) subtypes m1, m2, m3 and m4. Application of 100 microM acetylcholine (ACh) increased [Ca2+]i in all four subclones. The increased [Ca2+]i levels were significantly higher in m1- and m3-transformed cells than those in m2- and m4-transformed cells. In more than 95% of m2- and m4-transformed cells, [Ca2+]i showed sinusoidal oscillations. ACh-induced increases in [Ca2+]i were not observed in cells treated with an intracellular Ca2+ chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Removal of extracellular Ca2+ with ethylene-glycol-bis-(beta- aminoethyl)-N,N,N',N'-tetraacetate (EGTA) did not affect the initial [Ca2+]i increases, but reduced the late phases of delta [Ca2+]i in ml- and m3-transformed cells by 20-30%. Oscillations in m2- and m4-transformed cells persisted in EGTA solution (though sometimes slowed in frequency), suggesting that they were of intracellular origin. ACh-induced delta [Ca2+]i and inositol 1,4,5-trisphosphate formation was completely suppressed by pre-treatment with 50-100 ng ml-1 Pertussis toxin (PTX) for 12 h in m2- and m4-transformed cells, but not in m1- and m3-transformed cells. In all cells, extracellular application of caffeine and ryanodine, or intracellular application of cyclic adenosine diphosphate ribose (cAD-PR) produced a rise in [Ca2+]i. ACh-induced [Ca2+]i oscillations were not observed in ryanodine-treated m2-transformed cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1995

Technetium-99m tetrofosmin and technetium-99m sestamibi imaging of multiple metastases from differentiated thyroid carcinoma.

A 79-year-old male with follicular thyroid carcinoma metastasizing to the lung, bone and lymph nodes was subjected to whole-body scintigraphy using technetium-99m tetrofosmin and 99mTc-sestamibi. Both agents delineated the metastatic lesions and the two image qualities were comparable. We believe that 99mTc-tetrofosmin and 99mTc-sestamibi images may be helpful in localizing metastatic foci and substitute for thallium-201 in the follow-up of patients with differentiated thyroid carcinoma.

Adenocarcinoma, Follicular↗
PubMed1995

Metabolic profile of opioid peptides differs in the hippocampus and striatum of seizure-susceptible E1 mice.

We previously suggested that a deficit of anticonvulsant endogenous methionine enkephalin, in the cerebral cortex, septal area, hippocampus, and striatum of seizure-susceptible El mice plays a role in the pathogenesis of seizures. To determine whether a hypofunction of enkephalinergic neuron may be due to metabolic abnormalities of opioid peptides in the El mouse brain, we measured methionine enkephalin-like immunoreactivity (ME-LI) of 50 fractions eluted by high performance liquid chromatography obtained from those four regions of the brain of El and seizure-nonsusceptible ddY mice (the mother strain of El mice). We observed the same ME-LI patterns of 50 fractions in the cerebral cortex and septal area in El and ddY mice, whereas exhibited differing ME-LI patterns in the hippocampus and striatum in the two stains. Different ME-LI patterns may imply the difference in the metabolic profile of opioid peptides. Thus, an abnormal metabolism of opioid peptides in the hippocampus and striatum of the El mouse may be involved in the pathogenesis of seizures.

Animals↗
PubMed1995

HPLC/RIA analysis of bioactive methionine enkephalin content in the seizure-susceptible El mouse brain.

We previously reported a deficit of methionine enkephalin-like immunoreactivity (ME-LI), in the cerebral cortex, septal area, hippocampus, and striatum and the abnormal metabolism of opioid peptides in the hippocampus and striatum of seizure-susceptible El mice, which are involved in the pathogenesis of seizures. However, these findings suggest that the ME-LI does not necessarily reflect the bioactive methionine enkephalin (ME). Herein, we measured the biologically active peptide, ME excluding cross-reactive substances by using HPLC coupled with radioimmunoassay to clarify the abnormal function of enkephalinergic neurons in the El mouse brain. The ME content in 25-day-old El mice that had no seizures was significantly decreased in the hippocampus and septal area, as compared with corresponding regions in ddY mice (seizure-nonsusceptible; the mother strain of El). At the age of 50 days when El mice displayed abortive seizures, this content in both stimulated El[s] and nonstimulated El[ns] was significantly reduced in the septal area and cerebral cortex. At the age of 150 days when El mice exhibit tonic-clonic seizures, this content in both El[s] and El[ns] was significantly reduced in the septal area, cerebral cortex and striatum. These findings were generally compatible with our previous findings. This study further supports our hypothesis that a deficit of anticonvulsant endogenous ME, in the cerebral cortex, septal area, and hippocampus of seizure-susceptible El mice play an important role in the pathogenesis of seizures.

Animals↗
PubMed1995

A case of an intra-atrial tumor thrombus from hepatocellular carcinoma (HCC), first indicated by 67Ga-citrate scintigraphy.

We encountered a very rare case of an intra-atrial tumor thrombus from hepatocellular carcinoma (HCC). Conventional XCT and US gave evidence of HCC. In nuclear medicine studies performed incidentally, the first study with 99mTc-phytate liver scintigraphy showed 2 SOLs and evidence of chronic liver disease, and the second study with 67Ga-citrate scintigraphy demonstrated 2 hot lesions within the liver parenchyma, and also another unexpected hot area just above the left lobe of the liver, seemingly beyond the diaphragm. When echocardiography was performed, in addition to ECG, because the patient began to complain of dyspnea, an oblong mass lesion was detected within the right atrium. Reexamination with XCT and angiography clearly proved the existence of an intraatrial tumor thrombus. These results indicate the need for routine examination by echocardiography for HCC patients complaining of dyspnea.

Carcinoma, Hepatocellular↗
PubMed1995

A comparison of hard and soft copies processed with linear conversion and nonlinear conversion of skeletal fractures--a preliminary study.

To compare hard copies and soft copies processed with linear and nonlinear conversion of skeletal fractures, we performed a receiver-operating characteristics study of 25 digital radiographs. There was no statistical difference between hard copies with linear and nonlinear conversion. However, it may be difficult to detect small fractures on images processed by nonlinear conversion. No significant difference was seen between CRT diagnosis and that on a hard copy processed with linear conversion and frequency enhancement.

Adolescent↗
PubMed1995

Intraarterial infusion of dibutyryl cyclic adenosine monophosphate plus mitomycin C for unresectable hepatocellular carcinoma: long-term survival and response to tumor growth inhibition.

RATIONALE AND OBJECTIVES: Dibutyryl cyclic adenosine 3',5'-monophosphate (dBcAMP) has the capacity to promote morphologic differentiation and to inhibit tumor growth in vitro, but it has not been well researched in the clinical setting. In this study we examined the effects of intraarterial infusion of dBcAMP plus mitomycin C (MMC) on long-term survival and growth inhibition of tumors. METHODS: Thirty-one previously untreated patients with unresectable hepatocellular carcinoma (HCC) received intraarterial infusion of dBcAMP plus MMC. According to the International Union Against Cancer staging system, three patients had stage T3, eight had stage T4a, and 20 had stage T4b cancer. Growth inhibition was defined as no computed tomography (CT) scan evidence of increase in tumor diameter for at least 6 months after treatment. RESULTS: In all 31 patients with HCC, the cumulative survival rate was 34% at 1 year, 14% at 3 years, and 9% at 5 years. The median survival was 5.0 months, with the longest survival period being 92 months. Among 21 patients in whom a tumor response could be evaluated on the basis of follow-up CT studies, two had complete regression of their primary tumors. Overall, the response rate was 43% (9 of 21). Among the 12 stage T4b patients who had HCC that included the main trunk and its major branches of the portal vein, portal thrombi had disappeared in four (33%). Among eight patients who survived more than 1 year and were evaluated for tumor response using follow-up CT scan studies, six (75%) had growth inhibition of tumor. CONCLUSION: Chemotherapy combined with dBcAMP and MMC showed a favorable response in approximately one third of 31 patients who had unresectable HCC. Because of our results, combined therapy should be strongly considered in the treatment of patients with HCC including occlusion of the main portal vein.

Antibiotics, Antineoplastic↗
PubMed1995

Fibronectin and 130-kDa molecule complex mimics snake venom botrocetin-like structure potentially modulating association between von Willebrand factor and vascular vessel wall.

We established seven hybridomas secreting monoclonal antibodies (MoAbs) against the venom from Bothrops jararaca. Six of them were demonstrated to specifically recognize botrocetin, a venom protein which binds with von Willebrand factor (vWf) and induces platelet agglutination. Two of them, BCT4-3 and BCT115-2 MoAbs, could significantly inhibit botrocetin binding with plasma vWf. BCT4-3 could react slightly with a monolayer of human endothelial cells (ECs), and BCT4-3 binding to ECs was drastically enhanced by the coexistence of human plasma in a dose-dependent manner, indicating that a biological modulator structurally resembling botrocetin is created initially on the EC surface complexed with some plasma proteins. Botrocetin-like components could be immuno-purified only by immobilized BCT4-3, but not by the other immobilized MoAbs, from umbilical vein extracts. Interestingly, the immunoisolated materials were identified to consist essentially of fibronectin (Fn) and a 130 kDa molecule, and this complex bound to vWf in the extracts. Depletion of Fn from plasma decreased BCT4-3 binding to ECs. The epitope of BCT4-3 expressed on the endothelial surface, comprising plasma Fn and the coisolated 130 kDa molecule, is proposed to be a physiological modulator structurally mimicking botrocetin, and essentially supporting vWf-binding to injured endothelium and subsequently to circulating platelets.

Antibodies, Monoclonal↗
PubMed1995

A canine study of cold water drowning in fresh versus salt water.

OBJECTIVE: To compare the pathophysiologic changes occurring during drowning in cold fresh water and cold salt water with reference to viability. DESIGN: Randomized, prospective, controlled submersion experiments in two contrasting cold liquids. SETTING: A laboratory at a large university-affiliated medical institution. SUBJECTS: Thirteen healthy, anesthetized mongrel dogs. Three dogs served as controls and were immersed but not submerged. The remainder were submerged in cold fresh water or cold salt water (4 degrees C). INTERVENTIONS: Catheters were placed in the femoral artery, right carotid artery and right internal jugular vein. Electrocardiogram, pneumogram, and rectal temperatures were measured continuously during submersion/immersion. MEASUREMENTS AND MAIN RESULTS: Cold water submersion with drowning produced a large initial decrease in carotid artery temperature (approximately 7.5 degrees C in the first 2 mins) compared with a minor decrease (approximately 0.8 degrees C with immersion). No significant differences were noted in the rate of decrease of temperature between drowning in fresh water and salt water. During cold fresh water drowning, aspiration produced gross hemodilution with an average increase in body weight of 16.5%. Hematocrit values, serum sodium concentrations, and osmolality decreased while serum potassium concentrations, catecholamines, and free hemoglobin increased. All measured biochemical data (except PaO2) remained at viable levels. By contrast, during cold salt water drowning, average body weight increased by only 6%, with hemoconcentration and a shrinkage of vascular volume. Hematocrit and hemoglobin values increased by 30%, but initial plasma free hemoglobin values remained unchanged. Serum sodium concentrations, osmolality, and potassium concentrations increased rapidly to critical levels. CONCLUSIONS: On submersion in cold water, all of the experimental animals developed tachypnea immediately, followed by aspiration with predictable effects. The biochemical and pathophysiologic changes in cold water drowning approximated those changes reported for warm water drowning for both fresh and salt water with one exception and continued aspiration of cold water produced extremely rapid core cooling as long as the circulation remained intact. This process of acute submersion hypothermia may protect the brain temporarily from lethal damage, as reported in cases of cold fresh water drowning. Concentrations of circulating catecholamines increased exponentially in both groups of test animals. Clinically, their acute effects on the circulation, compounded by significant hypothermia and extreme anoxia, must hamper the detection of residual circulation at rescue and may play a role in sudden death from cold water in the absence of drowning.

Animals↗
PubMed1995

Impaired high-shear-stress-induced platelet aggregation in patients with chronic renal failure undergoing haemodialysis.

We investigated shear-induced platelet aggregation (SIPA) in 30 patients with chronic renal failure (CRF) undergoing haemodialysis. 26 patients showed a significant decrease in SIPA at high shear stress but no change in SIPA at low shear stress. The former reaction reflects the interaction between plasma von Willebrand factor (vWF) and its platelet receptors, glycoprotein (GP) Ib-IX and IIb/IIIa complex, whereas the latter is assumed to involve the binding of plasma fibrinogen to GP IIb/IIIa complex. These SIPA profiles in CRF patients after haemodialysis showed almost no change compared to those before haemodialysis. The ratio of ristocetin cofactor/vWF antigen in plasma was slightly lower in CRF patients than in controls (P < 0.01). However, the level of GPIb antigen in the platelets of these patients was significantly reduced (42.1 +/- 20.3% of normal platelets), with partial destruction of GPIb antigen. The number of vWF receptors on the GPIb molecule was quantitated using the GPIb-binding protein alboaggregin-B (AL-B), purified from the snake venom of Trimeresurus albolabris. AL-B bound to GPIb at a total of 48,760 +/- 9944 molecules per normal platelet and a Kd of 85.44 +/- 15.70 nM at saturation. In contrast, binding in CRF platelets was 22,980 +/- 6395 molecules per platelet and Kd was 50.08 +/- 13.83 nM. Taking these results together, we conclude that the impaired SIPA found in CRF patients is due to both abnormalities in plasma vWF and in its platelet GPIb receptor.

Adult↗